CN1184539C - Parts and imaging equipment capable of demountably connected to main body of imaging equipment - Google Patents

Abstract

The present invention relates to a component that can be detachably coupled to the main body of an image forming apparatus, it has a developing device for developing a latent image carried on an image carrier, and is used for storing A memory device for the elapsed time during a developing operation.

Description

Component capable of being detachably coupled to imaging device main body and imaging device

The present invention relates to image forming apparatuses such as xerographic copiers, facsimile machines and printers and components capable of being detachably coupled to the main body of the image forming apparatuses.

Among image forming apparatuses suitable for electrophotographic copiers, there is generally known such an image forming apparatus that prevents image density from greatly changing with various conditions such as changes in the use environment of the image forming apparatus and the number of printings, and every When performing image formation of a predetermined number of sheets, a developer image for density detection (hereinafter referred to as a patch) is always formed on a photosensitive drum as a latent image carrier, and the developer density of the patch is It is detected by an optical sensor or the like, and the detected developer density is fed back to image forming conditions such as developing bias in developing process conditions, so that image density control is performed so that the image density is maintained at a predetermined density level.

In the foregoing image density control, first, when the image density control is started, the image density control circuit provided in the image forming apparatus as adjustment means causes the pattern generation circuit to generate an image signal representing the density detection diaphragm, And based on this signal, latent images of n diaphragms P1 to Pn are formed on the photosensitive drum along the rotation direction. Subsequently, the latent image is developed by a developing device as developing means. At the same time, the high-voltage control circuit changes the developing bias (VDC) of each film, so that the films P1-Pn are separately developed as the developing biases V1-Vn vary. Densities D1 to Dn of the films P1 to Pn formed on the photosensitive drums are respectively measured by density sensors.

In the case where the latent image of the diaphragm for density detection is developed by different developing bias voltages (VDC), the relationship (V-D characteristic curve) between the developing bias voltage (VDC) and the density (O.D.) of the diaphragm becomes A curve like that shown in Figure 4. As seen in FIG. 4, the V-D characteristic curve is composed of parts A and C in which the characteristics change little and part B in which the characteristics change greatly. This V-D characteristic curve also varies by the environmental conditions in which the image forming apparatus is installed. For example, a characteristic curve as shown in FIG. 5 is obtained. In FIG. 5 , characteristic curve a is the same as characteristic curve a in FIG. 4 , characteristic curve b is a characteristic curve under high temperature and high humidity environment, and characteristic curve c is a characteristic curve under low temperature and low humidity environment.

As shown in FIG. 4, in the VD characteristic curve, the density change is unstable in the parts A and C, while the density change is steadily increasing in the part B. Therefore, as shown in FIG. 5, at the time of image density control, the control target density D _target is set at the B portion, and the developing bias voltages V1~Vn are set such that the densities D1~Vn of the corresponding diaphragms are set. Dn becomes D1<D2<...<Di<Di+1<...<Dn, and the control target density D _target is almost in the middle of the densities D1-Dn. The values of the developing bias voltages V1~Vn are set such that even when the VD characteristic curve changes slightly and the density values D1~Dn change, the control target density _Dtarget is still within the range of densities D1~Dn, and as shown in the figure The interval w between the developing bias Vi and the developing bias Vi+1 is set to about 50V.

As described above, since the VD characteristic curve greatly changes due to the influence of the environment, when the values of the developing bias voltages V1 to Vn are fixed, the characteristic curve b and the characteristic curve c shown in FIG. 5 are also fixed. , the control target density D _target deviates from the range of density D1～Dn. Then, the developing bias voltages V1˜Vn are also changed according to each environmental condition so that the control target density _Dtarget is almost in the middle of the densities D1˜Dn. For example, as shown in FIG. 6, in a high-temperature, high-humidity environment, developing bias voltages V1 to V4 are used for image density control.

When the image density control is started, in the developing bias voltage V1~Vn, the absolute humidity value in the imaging device is calculated according to the temperature and humidity sensors installed in the imaging device to select some applicable image density control at that time developing bias voltage. By using the densities D1~Dn of the corresponding films measured by the density sensor and the developing biases V1~Vn at the time of forming the corresponding films, the developing bias used to obtain the control target density D _target is calculated in the image density control circuit V _target optimal value.

The method for calculating the optimal developing bias V _target is as follows. First, find the interval containing the control target density D _target in the densities D1~Dn, that is, find the interval that can establish Di≤D _target≤Di +1 ( i～i+1). In the case where such an interval is found, linear interpolation based on Equation 1 is used to calculate the developing bias _Vtarget to obtain the _Dtarget .

(equation 1)

_Vtarget ={(Vi+1-Vi)/(Di+1-Di)}×( _Dtarget -Di)+Vi

The optimum developing bias _Vtarget is calculated using the above equation.

This developing bias V _target is stored in the memory, and imaging is performed by using this value until the next image density control is performed.

However, in such an image forming apparatus, the V-D characteristic curve varies not only by the environment in which the image forming apparatus is installed, but also by the driving state of the image forming apparatus. For example, similarly to the characteristic curve c shown in FIG. 7, the charge amount of the developer is temporarily lowered after a long rest state so that the V-D characteristic curve is shifted to the low density side.

Therefore, there is a concern that the control target density D _target is shifted from the range of densities D1 to Dn and errors occur. If the VD characteristic curve is further shifted by adding various conditions such as a reduction in the life of the developing device, the possibility of occurrence of errors is further increased.

In the event of an error, it is necessary to carry out a process to select the deficient developing bias previously set as the developing bias value _Vtarget . For example, the deficient developing bias is such an intermediate value between V1 and Vn that it is equal to V1 if _Dtarget <D1, or equal to Vn if Dn< _Dtarget .

In this case, only a minimum image can be secured, and an image with a stable density cannot be obtained. In order to suppress such a state to the limit, it can be considered to use such a method to widen the interval W between the corresponding developing biases V1~Vn, or increase the number of diaphragms to widen the controllable developing bias range. However, there is a problem that the error of linear interpolation becomes larger in a method of widening the interval between developing biases, or that the amount of developer consumed becomes larger in a method of increasing the number of diaphragms.

The decrease in the developer charge amount and the shift of the VD curve after quiescence are temporary, and when the image forming process is restarted, they quickly return to a stable state. Then, with the recovery of the charge amount, the V _target determined based on the temporary shift of the VD curve when the image density control is performed immediately after rest becomes an inappropriate value, making it impossible to obtain an image with a stable density. In order to suppress such a state to the limit, it may be considered to use a method of setting the execution interval of the image density control so short that an appropriate V _target is obtained after the recovery process of the charge amount. However, this causes image density control to be frequently performed, and as a result, the consumption of developer becomes large, which becomes a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a member which can be detachably attached to an image forming apparatus main body and which can obtain a stable developer density, and an image forming apparatus.

Another object of the present invention is to provide a developing device and an image forming apparatus which can be rapidly changed with changes in developing process conditions and image forming process conditions because the amount of charge therein has become very small after a rest state. copying so that an image with a stable developer density can be obtained without wasteful consumption of the developer.

Still another object of the present invention is to provide a kind of part that can be detachably coupled on the image forming apparatus main body, and it comprises the developing device that is used for developing the latent image that is carried on the image bearing body and the memory that has been stored from the developing device. Memory device for the elapsed time in the last developing job.

Yet another object of the present invention is to provide an image forming apparatus, which includes an image carrier for carrying a latent image, a developing device for developing the latent image carried on the image carrier, and a device for storing the latent images from the development. Memory device for the time elapsed in the last development job of the device.

Objects of the present invention other than the above objects and features of the present invention will become more apparent by reading the following detailed description and referring to the accompanying drawings.

1 is a schematic sectional view showing the structure of an image forming apparatus according to a first embodiment of the present invention;

2 is a graph showing the relationship between developing bias voltage and image density for explaining the image density control method of the third embodiment of the present invention;

3 is a graph showing the relationship between developing bias voltage and image density for explaining the image density control method of the fourth embodiment of the present invention;

Fig. 4 is a V-D characteristic graph showing the relationship between the developing bias voltage and the film density;

Fig. 5 is a graph showing the relationship between V-D characteristics and developing bias voltage and image density under respective circumstances, for explaining the method of determining the developing bias voltage for image density control;

6 is a graph showing the relationship between developing bias voltage and image density for explaining a method of determining a developing bias voltage for image density control in a high-temperature high-temperature environment;

Fig. 7 is a graph showing the relationship between V-D characteristics obtained immediately after rest and normal V-D characteristics;

Fig. 8 is a schematic sectional view showing the structure of an image forming apparatus according to a fifth embodiment of the present invention.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

(first embodiment)

Fig. 1 is a schematic sectional view showing the structure of an image forming apparatus according to a first embodiment of the present invention.

As shown in Fig. 1, the image forming apparatus comprises a drum-shaped photosensitive drum 1 as a latent image carrier on which an electrostatic latent image is formed on its outer peripheral surface; a roller charging device 2; an exposure device for forming a latent image by exposing the outer peripheral surface charged to a prescribed potential; an exposure device for converting the electrostatic latent image into a visible image by toner as a developer a developing device 4 ; a roll transfer roller 3 for transferring a visible image formed on the outer peripheral surface to a transfer paper P as a sheet-like recording material, and a fixing device 5 .

In FIG. 1, a photosensitive drum 1 is formed by applying an organic photosensitive material (OPC) or a photoconductor of A-Si, CdS, Se, etc. to an outer peripheral surface of an aluminum cylinder. The photosensitive drum is rotated by a driver (not shown) in the direction of the arrow in the drawing, and is uniformly charged to a predetermined potential by a roller charging device 2 .

The exposure device is placed on the upper part of the main body of the image forming apparatus, and it includes a laser diode 7, a polygon mirror 9 rotated by a high-speed motor 8, a lens 10, and a deflection mirror 11.

When an image signal is input in the laser driver 12, the laser driver 12 causes the laser diode 7 to emit light. Light from the laser diode 7 passes through the optical path 13, and the photosensitive drum 1 is irradiated with light having optical information corresponding to an image signal, thereby forming a latent image on the photosensitive drum 1.

Further, when the photosensitive drum 1 is rotated in the direction of the arrow, a voltage with a frequency of 800 to 3500 Hz and an amplitude of An AC voltage of 400 to 3000 V and an integrated average value VDC having a waveform of -50 to -550 V are superimposed on a developing bias of a DC voltage, so that the latent image is developed and becomes a toner image as a visible image. The toner image developed in this way is transferred onto transfer paper P as a recording material by the transfer roller 3 to which a predetermined bias voltage has been applied. The transfer paper P on which the toner image has been transferred is conveyed by a conveyor (not shown), and the toner image is melted and fixed on the transfer paper P by the fixing device 5, and becomes permanent. image.

Incidentally, the toner remaining on the photosensitive drum 1 is cleaned off by cleaning means 6 constituted by, for example, a brush, a scraper, or the like.

Next, control of image density in the image forming apparatus in this embodiment will be described.

In the image density control, first, when the image density control is started, the image density control circuit 19, which is an adjustment means provided in such an imaging device, causes the pattern generation circuit 15 to generate Based on the image signal of the film of the toner image, n film latent images P1 to Pn are formed on the photosensitive drum along the rotation direction. Subsequently, the latent image is developed by the developing device 4, and at the same time, the developing bias voltage (VDC) is changed for the corresponding diaphragm by the high-voltage control circuit 16, and the diaphragms P1-Pn are respectively developed by the developing bias voltage V1-Vn of. Densities D1 to Dn of the respective films P1 to Pn formed on the photosensitive drum 1 are respectively measured by a density sensor 17 as a detection means.

In the case where the latent image of the film for density detection is developed by different developing bias voltages (VDC), the relationship (V-D characteristic curve) between the developing bias voltage (VDC) and the density (O.D.) of the film becomes as follows As shown in Figure 4. As seen in FIG. 4, the V-D characteristic curve is composed of parts A and C in which the characteristics change little and part B in which the characteristics change greatly. This V-D characteristic curve is also changed by the environmental conditions in which the image forming apparatus is installed, and becomes a characteristic curve as shown in FIG. 5, for example. In FIG. 5 , characteristic curve a is the same as characteristic curve a in FIG. 4 , characteristic curve b is a characteristic curve under high temperature and high humidity environment, and characteristic curve c is a characteristic curve under low temperature and low humidity environment.

As shown in FIG. 4, in the VD characteristic curve, the density change is unstable in the parts A and C, while the density change is steadily increased in the part B. Therefore, as shown in FIG. 5, at the time of image density control, the control target density D _target is set at the B portion, and the developing bias voltages V1~Vn are set so that the densities D1~Dn of the corresponding diaphragms It becomes D1<D2<...<Di<Di+1<...<Dn, and the control target density D _target is almost in the middle of the densities D1-Dn. The values of the developing bias voltages V1~Vn are set such that even when the VD characteristic curve changes slightly and the values of the densities D1~Dn change, the control target density _Dtarget is still within the range of the densities D1~Dn, and as shown in the figure The interval w between the developing bias Vi and the developing bias Vi+1 is set to about 50V.

As mentioned above, since the VD characteristic curve is greatly changed by the influence of the environment, when the values of the developing bias voltages V1-Vn are fixed, the characteristic curve b and the characteristic curve d shown in FIG. 5 are also fixed, The control target density D _target is shifted from the range of densities D1-Dn. Then, the developing bias voltages V1˜Vn are also changed according to each environmental situation so that the control target density _Dtarget is almost in the middle of the densities D1˜Dn. For example, as shown in FIG. 6 , in a high-temperature high-temperature environment, developing bias voltages V1 to V4 are used for image density control.

When the image density control starts, among the developing bias voltages V1-Vn, according to the absolute humidity in the image forming apparatus calculated from the temperature and humidity sensor 18 installed in the image forming apparatus, some applicable ones at that time are selected. Developing bias for image density control. By using the densities D1˜Dn of the respective films measured by the density sensor 17 and the data of the developing biases V1˜Vn at the time of forming the respective films, a value for obtaining the control target density D _target is calculated in the image density control circuit 19. Optimum value of developing bias V _target .

A method for calculating the optimal value of the development bias V _target is as follows. First, find the interval containing the control target density D _target in the densities D1~Dn, that is, the interval where DI≤D _target≤Di +1 can be established (i~i+1). In the case where such an interval is found, a linear interpolation method based on Equation 1 is used to calculate the developing bias _Vtarget to obtain the _Dtarget .

(equation 1)

_Vtarget ={(Vi+1-Vi)/(Di+1-Di)}×( _Dtarget -Di)+Vi

The optimum developing bias _Vtarget is calculated using the above formula.

In the image forming apparatus according to this embodiment, as the memory means 20 provided in the image forming apparatus main body, this developing bias _Vtarget is maintained and image forming is performed until the next image density control is performed.

In the image forming apparatus of this embodiment, at first, four diaphragms P1˜P4 corresponding to four different developing bias voltages V1˜V4 are formed on the photosensitive drum 1, and after obtaining densities D1˜P4 corresponding to these diaphragms, After D4, find the interval containing the control target density D _target from D1 ~ D4. In the case where such an interval is found, the developing bias _Vtarget is calculated by interpolation in the linear interpolation represented by the foregoing Equation 1. Therefore, for proper image density control, the control target density D _target must be included in the diaphragm densities D1-D4.

Therefore, according to the image forming apparatus of this embodiment, a rest time counter (not shown) is included as a means for measuring the elapsed time (rest time) from the end of the previous image forming process (development process); memory means 20 of the elapsed time means measured by the counter; and means arranged to drive the developing device for a predetermined time based on the measured elapsed time (from the end of the previous imaging process to the receipt of the imaging processing instruction) After the sleeve 4a and the developer supply roller 4b, the image forming process starts.

That is, according to this embodiment, in the case where the rest time stored in the memory device 20 is some or more fixed values, when the image density control circuit 19 starts the image forming process again, the developing sleeve 4a and (will develop The developer supplying roller 4b of the developing sleeve 4a is driven for a predetermined time determined based on the rest time, and then the image forming process starts. Then, the image forming process is designed so as to be performed after the charge amount of the toner is lowered during the resting period. For example, when the rest time is TS (hours) and the driving time of the developing device is Td (seconds), driving is performed according to the relationship Td=αTs (where Td≤Td _{is large} ). The maximum value of the driving time Td of the developing device is the time Td _maximum that is Td at which a sufficient amount of toner charge can be obtained for the toner in a new developing device that does not supply any charge, and Calculation of the rest time Ts is performed until _Tsmax = _Tdmax /α. Also, a table showing the relationship between the rest time Ts and the driving time Td of the developing device may be provided in advance. Incidentally, either the developing sleeve 4a or the developer supply roller 4b may be driven for a predetermined period of time. Thereafter, it is possible to prevent the control target density D _target from deviating from the sheet densities D1 to D4 when the charge amount of the toner decreases, so that an image having a stable density can be obtained.

Incidentally, the memory means 20 housed in the main body of the image forming apparatus includes an area in which the value of variable T corresponding to the elapsed time (quiet time) from the end of the last image forming process (developing process) is written. At the start of the imaging process, zero is written as the T value in the memory device 20; after the imaging process ends, the T value is incremented by 1 every 5 minutes and written into the memory device. In terms of the accuracy of the resting time measurement, a value of 5 minutes is set as a value at which it is sufficient and appropriate to determine the time for performing the recovery process of the toner charge amount The value of can be set as required.

Then, according to this embodiment, the still time counting means measures the elapsed time from the end of the previous image forming process, and based on the measured elapsed time from the previous image forming process to the reception of the image forming process instruction, the developing sleeve 4a and The developer supply roller 4b is driven for a predetermined time, and then, the image forming process is started. Then, the developing sleeve 4a and the developer supply roller 4b charge the toner, and since the amount of charge decreases as the toner goes away from the end of the previous image forming process to when the image forming process instruction is received, So that the toner is not wasted wastefully, and an image with a stable toner density can be obtained.

(second embodiment)

Next, an image forming apparatus according to a second embodiment of the present invention will be described. Incidentally, as for the same structure as the first embodiment, its description is omitted.

According to this embodiment, in the case where the count value of the still time counting means becomes some or more constant values, when the image density control circuit 19 starts the imaging process again, the image density control is executed at such an interval On, the execution interval between the first image density control performed immediately after the still is canceled and the second image density control performed next is set to be shorter than the normal interval so that the A suitable V _target can be obtained according to the recovery of the dose charge. Also, the image density control of the execution interval after the second image density control is not performed immediately after the still mode is canceled, and in the case of performing image formation of a predetermined number of sheets, it is the same as that used as Image formation is the same for the same number of sheets under normal conditions, so that an image with stable density can be obtained while avoiding wasteful consumption of toner.

Then, according to this embodiment, the static time counting means measures the elapsed time from the end of the previous imaging process, and based on the measured elapsed time from the end of the previous imaging process to the start of the imaging process, the image density control circuit 19 Shorten the adjustment interval from the start of the image forming process to several adjustments of toner density. Thus, it is possible to quickly perform copying while the conditions of the image forming process change, since the amount of charge of the toner has decreased as it goes away from the end of the previous image forming process to the time the image forming process command is received, Thereby, the toner is not consumed wastefully and an image having a stable toner density can be obtained.

(third embodiment)

Next, an image forming apparatus according to a third embodiment of the present invention will be described. Incidentally, as for the same structure as the first embodiment, its description is omitted.

According to this embodiment, in the case where the count value of the rest time counting means becomes some or more constant values, when the image density control is performed for the first time after restarting after the imaging process, the development of the normal diaphragm formation is not used. Bias voltage V1～V4, but as shown in Figure 2, the bias voltage when the imaging device (not shown) starts to form the diaphragm changes from V1 to V1' according to the VD characteristic curve due to static, and V2～V4 all have similar Changes, so that the diaphragm is formed by using the bias voltages V1'~V4'. Therefore, it is possible to prevent an error such that the D _target deviates from the range of the diaphragm densities D1' to D4'. By varying the initial bias of the diaphragms, it is possible to perform measurements without increasing the number of diaphragms and without greatly increasing the interval w, thereby suppressing the increase in error that occurs when calculating using the interpolation method of Equation 1, and An image with stable density can be obtained without wasteful consumption of toner. Incidentally, characteristic curve a and characteristic curve c shown in FIG. 2 are the same as characteristic curve a and characteristic curve c shown in FIG. 5 .

Then, according to this embodiment, the still time counting means measures the elapsed time from the end of the previous image forming process, and based on the measured elapsed time from the end of the previous image forming process to the start of the image forming process, the image forming means performs A toner image is formed on 1 while the image forming process conditions are changed from the start of the image forming process to the first adjustment. Thus, it is possible to quickly perform copying while the conditions of the image forming process are changed, since the amount of charge of the toner has decreased as it goes away from the end of the previous image forming process to when the image forming process instruction is received, thereby The toner is not consumed profligately and an image having a stable toner density can be obtained.

(fourth embodiment)

Next, an image forming apparatus according to a fourth embodiment of the present invention will be described. Incidentally, as for the same structure as the first embodiment, its description is omitted.

According to this embodiment, in the case where the count value of the still time counting means becomes some or more constant values, when the execution of the image density control for the first time is restarted after the imaging process, as shown in FIG. 3, the imaging means (Not shown) The films P1 to P6 are formed using six developing biases V1 to V6 which are two more than the normal four. Although the interval w of the developing bias for forming the respective patches is the same, the number of patches is increased so that a wide range can be covered, and therefore, it is possible to prevent the D _target from deviating from the range of patch densities D1 to D6. error. Since the spacing w of the diaphragms does not change, there is no increase in the error that occurs when calculating using the interpolation method of Equation 1. In addition, the number of diaphragms is increased only when the first image density control immediately after canceling the still is cancelled, so that toner consumption does not increase significantly and an image with stable density can be obtained. Incidentally, characteristic curve a and characteristic curve c shown in FIG. 3 are the same as characteristic curve a and characteristic curve c shown in FIG. 5 .

Then, according to this embodiment, the still time counting means measures the elapsed time from the end of the previous image forming process, and based on the measured elapsed time from the end of the previous image forming process to the start of the image forming process, the image forming means performs 1, and the conditions of the image forming process from the start of the image forming process to the first adjustment are various. Thus, it is possible to quickly perform copying while the conditions of the image forming process are changed, since the amount of charge of the toner has decreased as it goes away from the end of the previous image forming process to when the image forming process instruction is received, thereby The toner is not consumed profligately and an image having a stable toner density can be obtained.

(fifth embodiment)

Next, an image forming apparatus according to a fifth embodiment of the present invention will be described. Incidentally, as for the same structure as the first embodiment, its description is omitted.

In this embodiment similar to the first embodiment, in the case where the rest time stored in the memory device 20 is some or more constant value, after the developing sleeve 4a and the developer supply roller 4b are driven for a certain period After a predetermined time depending on the above-mentioned quiescent time, the imaging process is started so that the amount of charge reduced during the quiescent period is recovered.

In the first embodiment, a structure is available in which the memory means 20 storing the still time is provided in the main body of the image forming apparatus as shown in FIG. However, in this embodiment, as shown in FIG. 8, the memory unit 20 is provided in a developing unit detachably coupled to the main body of the image forming apparatus.

In the first embodiment, since the information on the charge amount of the toner in each developing device cannot be obtained from the memory device provided in the main body of the image forming apparatus, even when, for example, the user repeatedly In the case where the developing device mounted on the main body of the image forming apparatus is replaced with a developing device having a sufficient amount of toner charge, in order to drive the developing sleeve 4 for a predetermined period of time, it is impossible to omit Such an unnecessary process of charging the toner is similar to the case of installing a new developing device.

In this embodiment, such a structure is employed that the memory means is mounted on the side of a part detachably coupled to the main body of the image forming apparatus. Thus, even in the case where the user repeatedly exchanges the developing devices, it is possible to correctly read the time elapsed from the last image forming process performed by each developing device and to perform toning for only a necessary and sufficient time. agent charging process. Incidentally, in the memory means provided for a new developing device, _Tsmax proposed in the first embodiment is stored as the elapsed time from the last image forming process.

Then, according to this embodiment, the still time counting means measures the elapsed time from the end of the previous image forming process, and drives the developing sleeve 4a and the developer supply roller 4b for a certain period according to the received elapsed time of the next image forming process instruction. A scheduled time, then, begins the imaging process. Then, the developing sleeve 4a and the developer supply roller 4b charge the toner because the amount of charge has been reduced as the toner has gone from the end of the previous image forming process to the time the instruction for the next image forming process is received. reduce. In addition, the memory means for storing the elapsed time is not attached to the main body of the image forming apparatus, but is attached to a part detachably coupled to the main body of the image forming apparatus, so that it is possible to perform correct copying with parts such as exchange, And an image with stable toner density can be obtained without being wasteful in toner consumption.

(sixth embodiment)

Next, an image forming apparatus according to a sixth embodiment of the present invention will be described. Incidentally, as far as the structure of the fifth embodiment is the same as that of the first embodiment, its description is omitted.

In this embodiment, which is similar to the second embodiment, in the case where the static time stored in the memory is some or more constant value, in the first image density control immediately after the static is cancelled. The execution interval between the subsequent second image density control is set to be shorter than the normal interval, and the image density control is performed, so that an appropriate V _target can be obtained according to the recovery state of the charge amount of the toner. The image density control of the execution interval after the second image density control is not performed immediately after the still mode is canceled, and it is the same as the normal case in the case of performing image formation of a predetermined number of sheets The image formation of the number of sheets is the same, so that an image with stable density can be obtained while avoiding wasteful consumption of toner.

However, since the memory device storing the still time is not attached to the image forming apparatus main body but is attached to a part detachably coupled with the image forming apparatus main body, it is possible to perform correct copying along with parts such as exchange, and can An image with stable toner density is obtained without toner being wastefully consumed.

(seventh embodiment)

Next, an image forming apparatus according to a seventh embodiment of the present invention will be described. Incidentally, as far as the configuration of the sixth embodiment is the same as that of the first embodiment, its description is omitted.

In this embodiment similar to the third embodiment, when the imaging process is resumed after resting, the rest time stored in the memory is some or more constant value, after restarting the imaging process When the image density control is performed for the first time, the developing biases V1-V4 for normal film formation are not used, but the bias voltage V1' for starting film formation is used as shown in FIG. And the changing VD characteristic curve changes V1 to V1', and V2-V4 also changes similarly, so the diaphragm is formed by using bias voltages V1'-V4'. Therefore, it is possible to prevent an error such that the D _target deviates from the range of the diaphragm densities D1' to D4'. By changing the initial bias for forming the patches, it is possible to perform copying with a reduced charge amount of the toner without increasing the number of patches and without greatly increasing the interval w. It is thereby possible to suppress an increase in error occurring in calculation using the interpolation method of Equation 1, and to obtain an image having a stable density without wasteful consumption of toner.

However, since the memory device storing the still time is not mounted on the image forming apparatus main body but is mounted on a part detachably coupled with the image forming apparatus main body, it is possible to correctly copy along with parts such as exchange, and An image with stable toner density can be obtained without toner being wastefully consumed.

(eighth embodiment)

Next, an image forming apparatus according to an eighth embodiment of the present invention will be described. Incidentally, as far as the structure of the seventh embodiment is the same as that of the first embodiment, its description is omitted.

In such an embodiment similar to the fourth embodiment, when the imaging process is restarted after resting, in the case where the resting time stored in the memory is some or more constant value, when restarting the imaging process When the image density control is performed for the first time later, as shown in FIG. 3 , the diaphragms P1 to P6 are formed using six developing biases V1 to V6 which are two more than the normal four biases. Although the interval w of the developing bias for forming the respective films is the same, the number of films is increased so that a wide range can be covered, and therefore, it is possible to prevent the D _target from deviating from the range of film densities D1 to D6. error. Since the spacing w of the diaphragms does not change, there is no increase in the error that occurs when calculating using the interpolation method of Equation 1. In addition, the number of diaphragms is increased only when the first image density control performed immediately after the rest is cancelled, so that an image having a stable density can be obtained while toner consumption does not significantly increase.

However, since the memory device storing the still time is not mounted on the image forming apparatus main body but is mounted on a part detachably coupled with the image forming apparatus main body, it is possible to correctly copy along with parts such as exchange, and An image with stable toner density can be obtained without toner being wastefully consumed.

By the way, although the fifth embodiment to the eighth embodiment show examples in which the developing device includes a memory device, such a structure can be used in a process cartridge including an image carrier, and at least the developing device includes a memory device. device.

Imaging equipment as described above, including:

an image carrier carrying a latent image;

A developing device for developing a latent image carried on the image carrier: and

Memory means for storing the time elapsed since the last developing operation of the developing means.

In addition, the imaging device also includes:

an image density control device for detecting the image density of the developer for density detection and controlling the image density based on the detected density;

in

The image density control is performed by the image density control means in case the time stored in the memory means is one or more predetermined times when the developing means starts the developing operation.

In addition, during image density control, the image density control device sets a developing bias to obtain a desired image density.

In addition, the developing device includes a developer carrier carrying the developer, and the developer carrier is driven for a predetermined time before starting the developing operation.

In addition, the rotation time of the developer carrier is determined based on the time stored in the memory device.

In addition, the rotation time of the developer carrier is proportional to the time stored in the memory device.

In addition, the developing device includes a developer supply member for supplying the developer to the developer carrier, and the developer supply member is also driven before starting the developing operation.

In addition, in the case where the time stored in the memory means is one or more predetermined times, the first image density control by the image density control means and the subsequent image density control by the image density control means The interval between executions is shorter than the normal execution interval.

Furthermore, in the case where the time stored in the memory means is one or more predetermined times, in the first image density control performed by the image density control means, the image density control means for density detection detects that the The density of the developer image is formed by a developing bias different from the normal developing bias, and the density of the image is controlled based on the detected density.

In addition, when the time stored in the memory means is one or more predetermined times, the number of developer images used for density detection in the first image density control by the image density control means , greater than the number of normal developer images used for density detection.

In addition, the developing device includes a developer carrier that carries the developer, and applies a bias voltage of a DC voltage superimposed on the AC voltage between the developer carrier and the image carrier.

Additionally, components that can be detachably coupled to the main body of the imaging device include:

a developing device for developing a latent image carried on an image carrier; and

A memory device for storing the time that has elapsed from the last developing operation of the developing unit.

Furthermore, the component is a process cartridge including an image carrier.

Claims (23)

1. A component capable of being detachably attached to an imaging device body, the component comprising: a developing device for developing a latent image carried on an image carrier using a developer; and memory means for storing the time that has elapsed since the last developing operation of said developing means; Wherein, the main body is capable of giving charge to the developer when the part is not in use, and the main body is capable of giving charge according to the time stored in the memory device when the part is not in use. developer handling; Also, the time in which the operation of giving charge to the developer is performed when the member is not in the unused state is performed is shorter than the time in which the operation of giving charge to the developer is performed when the member is in the unused state. 2. The component according to claim 1, wherein said image forming apparatus main body includes image density control means for detecting the density of a developer image for density detection, and controlling the image density according to the detected density. density, Wherein, in a state where the component is mounted in the image forming apparatus main body, in the case where the time stored in the memory means when the developing means starts a developing operation is one or more predetermined times , performing image density control by the image density control device. 3. A member according to claim 2, wherein said image density control means sets the developing bias so as to obtain a desired image density as a result of the image density control. 4. The unit according to claim 1, wherein said developing means includes a developer bearing member for bearing the developer, and the operation of imparting charge to the developer is a driving of said developing means for a predetermined time before starting a developing operation. Handling of the developer carrier. 5. The unit according to claim 4, wherein the operation of driving said developer carrier is a rotational driving operation, and the rotation time of said developer carrier is determined based on the time stored in said memory means. 6. The member according to claim 5, wherein the rotation time of said developer bearing body is determined to be proportional to the time stored in said memory means. 7. The unit according to claim 6, wherein said developing device includes a developer supply member that supplies developer to said developer carrier, and said developer supply member is driven before a developing operation starts. 8. The component according to claim 2, wherein said image density control means performs image density control for each image forming a predetermined number of sheets, and the time stored in said memory means is one or more predetermined times In the case of , the execution interval between the first image density control performed by the image density control means and the subsequent image density control performed by the image density control means is shorter than that performed every time a predetermined number of images are formed. The execution interval of the image density control. 9. The component according to claim 2, wherein when the time stored in the memory means is one or more predetermined times, when the image density control is performed for the first time by the image density control means, the image The density control means detects a density of a developer image for density detection by using a developing bias different from a normal developing bias, and controls the image density based on the detected density. has been formed. 10. The component according to claim 2, wherein in the case where the time stored in the memory means is one or more predetermined times, the time used in the first image density control performed by said image density control means The number of developer images for density detection is larger than the number of normal developer images for density detection. 11. The component according to claim 1, wherein said component is a process cartridge including said image carrier. 12. The member according to claim 2, wherein said developing means includes a developer bearing body that carries a developer, and a developing bias voltage of a DC voltage superimposed on an AC voltage is applied to said developer bearing body and said image. between carriers. 13. An imaging device comprising: an image carrier for carrying a latent image; a developing device for developing a latent image carried on an image carrier using a developer; and memory means for storing the time that has elapsed since the last developing operation of said developing means; Wherein, the main body of the image forming device is capable of performing an operation of giving charge to the developer when the developing device is in an unused state, and the main body is capable of performing an operation of giving charge to the developer when the developing device is not in an unused state according to the The time of storage to perform the operation of imparting charge to the developer; Also, the time in which the operation of giving charge to the developer is performed when the developing device is not in the unused state is performed is shorter than the time in which the operation of giving charge to the developer is performed when the developing device is in the unused state. 14. The image forming apparatus according to claim 13 , further comprising image density control means for detecting the density of the developer image for density detection and controlling the image density based on the detected density, Wherein, in the case that the time stored in the memory means when the developing means starts a developing operation is one or more predetermined times, the image density control is performed by the image density control means. 15. The image forming apparatus according to claim 13, wherein said image density control means sets the developing bias so as to obtain a desired image density as a result of the image density control. 16. The image forming apparatus according to claim 13, wherein said developing means includes a developer carrier for carrying the developer, and the operation of giving electric charge to the developer is a driving of said developing means for a predetermined time before starting a developing operation. Handling of the developer carrier. 17. The image forming apparatus according to claim 16, wherein the operation of driving said developer carrier is a rotational driving operation, and the rotation time of said developer carrier is determined based on the time stored in said memory means . 18. The image forming apparatus according to claim 17, wherein a rotation time of said developer carrier is determined to be proportional to a time stored in said memory means. 19. The image forming apparatus according to claim 18, wherein said developing device includes a developer supply member that supplies developer to said developer carrier, and said developer supply member is driven before a developing operation starts. 20. The image forming apparatus according to claim 13, wherein said image density control means performs image density control to images of a predetermined number each time, and is stored in said memory means for one or more predetermined times. In the case of time, the execution interval between the first image density control performed by the image density control device and the subsequent image density control performed by the image density control device is shorter than the predetermined number of sheets for each formation The interval at which the image density control is performed for the image. 21. The image forming apparatus according to claim 13, wherein when the time stored in the memory means is one or more predetermined times, when the image density control is performed for the first time by said image density control means, said The image density control means detects the density of a developer image for density detection, wherein the developer image for density detection is developed by using a developing bias different from normal, and controls the image density based on the detected density. bias has been established. 22. The image forming apparatus according to claim 13, wherein when the time stored in the memory means is one or more predetermined times, it is used for the first image density control performed by said image density control means The number of developer images for density detection in is larger than the number of normal developer images for density detection. 23. The image forming apparatus according to claim 13, wherein said developing means includes a developer carrier carrying a developer, and a developing bias of a DC voltage superimposed on an AC voltage is applied to said developer carrier and said developer carrier. between image carriers.

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